Many enclosure assemblies used in the windows of structures which have a large window area to wall area ratio (e.g., porches, structures around swimming pools, greenhouses, and animal shelters) comprise a frame defining a through opening over which screen extends, and panels comprising sheets of transparent material (e.g., polymeric material or glass) that may be slid along tracks or pivoted at their edges between closed and open positions to respectively extend across or uncover portions of the screened opening. In their open positions, sliding panels typically cover large portions of such openings and, if such panels are large, they can be difficult to move and can stick in their tracks. Pivotal panels remain in the line of vision when they are open. With either type of panels, a designer must choose between (1) minimizing the framing around the transparent material in the panels, which minimizes the open feeling of the enclosure assemble, but limits the panel size and allows the transparent material to be more easily broken due to the minimal support by the framing; or (2) using more framing which allows larger panels to be used but reduces the visibility through or past the panels in either their open or closed positions.
My U.S. Pat. No. 4,524,814 issued June 25, 1985, (incorporated herein by reference) describes an enclosure assembly which is particularly useful in the windows of structures where a large window area to wall area ratio is desired, which enclosure assembly has good strength with a minimum of framing and can be either (1) closed so that panels cover an opening, (2) partially opened so that alternating panels and lengths of screen cover the opening, or (3) fully opened to totally uncover the opening.
That enclosure assembly includes a plurality of stiff elongate generally rectangular panels, and means mounting the panels in edge-to edge relationship for edgewise sliding movement along a predetermined path across the opening to afford relative movement of adjacent panels between (1) a closed position with panel edges of the adjacent panels together so that several pairs of adjacent panels in their closed positions can cover the opening; and (2) a spaced position with the adjacent panels spaced apart and lengths of flexible material, many of which are screen, attached between the panels extending across the space between the adjacent panels so that with one or more spaced adjacent panels across the opening some of the opening will be covered only with screen. Means are provided for relatively moving adjacent panels across the opening between their closed and spaced positions, and for further moving all of the panels and lengths of flexible material or screen interconnecting them completely away from the opening so that the opening is free from any obstruction. Such means for moving the panels can comprise a frame defining the opening and the path, which frame has a top, guide means for positioning the panels across the opening one above the other with the panel edges extending horizontally and positioned vertically one above another, and support means adapted to engage and support the bottom edge on the lowermost panel of a stack of adjacent panels in their closed positions and covering the opening. Means are also included which may be in the form of a manually rotatable spindle at the top of the frame adapted to roll on the panels and their interconnecting lengths of flexible material or screen, for sequentially lifting the panels out of the top of the frame to sequentially move adjacent panels in the stack covering the opening to their spaced positions downwardly from the top of the frame until the opening is covered by adjacent panels in their spaced positions with interconnecting lengths of screen between the panels and the enclosure assemble is in the partially open position, and to subsequently lift all of the panels out of the top of the frame so that the enclosure is fully open with none of the panels or strips of flexible material extending across the opening.
The panels preferably each comprise an elongate slat that is of an opaque, translucent, or transparent stiff material such as Plexiglas or fiberglass, or which could be of another suitable decorative material such as wood or a thermal insulating material such as polystyrene. The panels additionally can have their panel edges adapted to nest together generally in the manner of a tongue and groove to restrict movement of air and moisture between adjacent panels when they are in their closed positions. The lengths of screen are held along corresponding sides of adjacent panels they interconnect by strips defining the longitudinal panel edges in a manner that causes the lengths of screen to bend generally into cylindrical projections from those corresponding sides when the adjacent panels they interconnect are in their closed positions, and which causes the lengths of screen to be tensioned around and between the strips when the adjacent panels they interconnect are separated.
While that enclosure assembly is quite acceptable and provides many advantages in many structures, it has been found to have certain disadvantages. The use of screen as the flexible material allows more air and moisture infiltration than may be desired between adjacent panels despite their tongue and groove like mating edges, and the appearance of large cylindrical projections of screen adapted to be stretched between panels is objectionable to some. The enclosure assembly is not capable of providing 100 percent ventilation through the opening with screen across the entire opening to prevent passage of bugs. Also, the widths of the panels are limited by use of three equally spaced support edges on the spindle by which the panels are lifted.